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How do I know if I have a factory-fitted immobiliser?

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November 30, 2018
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If you’re in the process of buying a car or car insurance, you’ve probably noticed the term ‘factory-fitted immobiliser’ cropping up in vehicle specifications, insurance quote calculators and policy documents. But what exactly does it mean?

What is an immobiliser and how does it work?

Essentially, an immobiliser is an electronic device that prevents a vehicle from being started unless the correct key is used or specific key fob is present. A factory-fitted immobiliser is one that is fitted at the point of manufacture. 

When you climb into your car and insert your key, the key or its fob sends a code to the electronic control unit (ECU), informing the car that it has permission to start the engine. If a thief was to gain entry and attempt to steal the car by hotwiring it or using an incorrect key, the ECU would not receive that all-important code. In this case, the immobiliser would activate and prevent the engine from running.

Immobilisers usually work by disabling two of the three main components involved in making the car start (i.e. the fuel system, the starter motor and/or the ignition).

Other types of immobiliser are available. Some require the driver to insert a touch key or to manually enter a PIN code sequence into the system using buttons on the central console, steering wheel and/or door panels. Some devices can even receive an encrypted code from a smartphone app via Bluetooth.

Does my car have an immobiliser?

You’re probably thinking, that sounds great but how can I tell if my car has an immobiliser when all of the technology is hidden away inside keys, fobs and ECUs?

Well, the good news is that factory-fitted immobilisers have been compulsory additions to new cars sold in the UK since October 1998. So, if your vehicle was made after this date you can be pretty certain that it has one (providing no former owners have had it removed or disabled). You can double-check by consulting your vehicle handbook, which is usually kept with the car (in the glove compartment) or can be downloaded online from the manufacturer’s website.  

Cars that have been imported or were manufactured before October 1998 may not boast a factory-fitted immobiliser, but could have had an aftermarket immobiliser (ie one fitted after manufacture) installed by a past owner. Again, be sure to check the handbook and ask the seller.

If this isn’t possible, you can ask a mechanic to inspect your vehicle. If your chosen car doesn’t already have an immobiliser, you can, if you wish, arrange for one to be fitted under your ownership.

How can an immobiliser benefit me?

Whether you fill in an online form or speak to a customer service advisor over the phone, one of the standard questions insurance companies will ask is whether your vehicle has an alarm and/or immobiliser fitted.

This is because such devices have a huge bearing on car security. The more secure the car, the less likely it is to be stolen – and if an insurer considers you to be low-risk, then it will usually reward you with lower insurance premiums.

Of course, technology isn’t infallible, but if your car has an immobiliser or you choose to have one fitted, you can enjoy the dual benefits of cheaper insurance (with some providers) and a much better chance of your vehicle staying where you left it!

What sorts of immobilisers are best?

Factory-fitted immobilisers are often seen as preferable because it’s assumed that they are fit for purpose and installed correctly. But, if your car doesn’t have one, it’s not the end of the world as you can always have one fitted. Just make sure you opt for a Thatcham-approved aftermarket device.

Thatcham Research is a not-for-profit motor insurance repair research centre, set up in 1969 to help minimise the cost of motor insurance claims and maintain safety standards. As part of its work, the organisation launched a set of categories for alarms and immobilisers in the 1990s, which have since become an industry benchmark. 

Security systems and devices are rigorously tested for functionality, design and performance before they can achieve certification and be assigned one of the Thatcham categories, based on their type.

Immobilisers and alarms are deemed the most effective method of security, falling into ‘Category 1: electronic alarm and immobiliser’ and ‘Category 2: electronic immobiliser’ (ie a Category 1-standard immobiliser but with no alarm function). These are followed by mechanical immobilisers such as steering wheel locks in Category 3; wheel-locking nuts in Category 4; and different types of tracking devices in 5, 6 and 7.

Once you’ve chosen your immobiliser, the next step is to find an expert security system installer. Thatcham Fitters and the Mobile Electronics and Security Federation hold databases of approved installers who should be suitably qualified and skilled to fit your device correctly.

In summary

While immobiliser technology is usually tucked away out of sight, in the inner workings of your car and key, its widespread presence in both modern and older cars makes it an effective deterrent against would-be thieves. And if anyone is bold enough to attempt a break-in, they aren’t likely to get very far!

But the most tangible benefit for vehicle owners is surely the reduction in annual premiums that can often be gained by proudly selecting ‘Thatcham-approved immobiliser’ in a car insurance application.

The important thing to remember is that quality counts, so always make sure that you have a Thatcham-approved device, fitted at point of manufacture or by a reputable aftermarket installer.

Learn more about protecting your car from would-be thieves.

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